Mac: One of the minor annoyances for some people on a MacBook is that you can't customize the mouse acceleration settings by device. Acceleration is great for trackpads, but often it's awkward with a mouse. Smooth Cursor is an app that allows you to change the acceleration by device.

Smooth Cursor allows you to control the acceleration for both a mouse and a trackpad separately. So, if you like the feature on one of your inputs, you can use it and customize it while disabling it the other. It's a simple app, but it takes care of one of the annoyances on Mac laptops that has bugged me for years.